Human Health + Systems

Question 1

Ingestion/eating

Answer 1

Food is taken in by the body

Question 2

Digestion

Answer 2

Food is broken down here

Question 3

Absorption

Answer 3

Digested food passes into the bloodstream

Question 4

Assimilation

Answer 4

Using the food in the cells of the body

Question 5

Elimination

Answer 5

Getting rid of undigestedfood

Question 6

Physical digestion

Answer 6

Mouth with your teeth and stomach with your churning

Question 7

Chemical digestion

Answer 7

Uses enzymes to break down food

Question 8

Enzymes

Answer 8

Are chemicals that sped up reactions without being used up in the reaction

Question 9

Enzymes

Answer 9

Act on a substrate and breaks it down into a product

Question 10

Example

Answer 10

Substrate = starch , enzyme = amylase (saliva) , product = maltose (sugar)

Question 11

Plasma

Answer 11

Liquid part of the blood
Pale yellow -mostly water
Function : to transport chemicals and heat
-chemicals (useful) : food , hormones
- chemicals (waste) : CO2, salts , urea
- heat : generated from chemical reactions , transported around to maintain 37 degrees Celsius

Question 12

Red blood cells

Answer 12

Round, flattened discs, curve inward near centre
• Small, no nucleus, formed in bone marrow
• Very numerous – approx 5million per drop blood
• Function : transport oxygen to cells
• Red colour comes from haemoglobin
they contain.
• Haemoglobin picks up oxygen in the lungs
• It later releases it in other parts - e.g. muscle

Question 13

Whit blood cells

Answer 13

Larger than Red Blood Cells but fewer in number
• No definite shape – shape can change
• They are also made in the bone marrow
• Function : to fight infection
• Some can surround micro-organisms and destroy them
• Others produce proteins called antibodies
• Antibodies help to destroy micro-organisms such as bacteria

Question 14

Platelets

Answer 14

Smaller than red or white blood cells
• They are formed in the bone marrow
• They are formed from larger cells breaking down into pieces
• Function: help to form blood clots
• When a blood vessel is injured, platelets help to form a clot
• Clotting prevents loss of blood, and prevents micro- organisms getting in
• Clots are temporary barriers while repair and healing is taking place

Question 15

System of tubes + pump

Answer 15

Blood being a fluid, needs tubes in which to flow
• These tubes are called blood vessels
• They come in three main types:
– Arteries
– Veins
– Capillaries
• Good blood flow requires the aid of a good pump
• In the human circulatory system this pump is the heart
• In an average lifetime, the heart beats more than 2.5 billion times, without ever pausing to rest

Question 16

Arteries

Answer 16

Blood being a fluid, needs tubes in which to flow
• These tubes are called blood vessels
• They come in three main types:
– Arteries
– Veins
– Capillaries
• Good blood flow requires the aid of a good pump
• In the human circulatory system this pump is the heart
• In an average lifetime, the heart beats more than 2.5 billion times, without ever pausing to rest

Question 17

Veins

Answer 17

• Carry blood BACK to the heart
• Flow of blood is weaker and pressure is low
• Vein walls are thinner and weaker than artery walls
• Pressure is low, so there is a danger of backward flow of blood, especially when flow direction is against gravity
• Valves in veins at regular intervals, allow blood to flow forwards, but prevent reverse flow
• All veins (except pulmonary vein) carry deoxygenated blo

Question 18

Capillaries

Answer 18

• These are tiny blood vessels
• There are a huge number of them in the body
• Capillaries are found between arteries and veins
• Capillaries have very thin walls which allow materials to pass in and out with the surrounding cells and tissue.

Question 19

The heart

Answer 19

Is an organ about the size of a clenched fist
• Function: pumps blood around the body
• It pumps blood by contracting periodically
• Cardiac muscle provides the contraction
• Unlike regular muscle, cardiac muscle doesn’t tire easily
• Resting heart rate in adults is about 72 bpm(beats per minute)
• In exercise, the heart beats faster, so that the blood can carry chemicals faster around the body e.g. Oxygen

Question 20

Pulse rates

Answer 20

• When the heart contracts, it squeezes blood into the arteries under pressure.
• As blood flows down the arteries, surges of pressure can be felt where the arteries are close to the surface
• Areas where it can be felt are:
– Atthewrist
– Innerarmnearelbowjoint – Atthesidesoftheneck
• A surge of blood felt at these locations is called a pulse
• The pulse rate is at the same pace as the heart rate

Question 21

Ingredients for engery

Answer 21

• We’ve learned in digestion that food is absorbed into our bloodstream and carried around to all the cells in our body!
• The process that releases energy from this food is RESPIRATION.

Question 22

Respiration is the release of energy from food.

Answer 22

• The equation for respiration in words is:
• Glucose + Oxygen Carbon dioxide + Water + Energy

Question 23

Type of respiration

Answer 23

• Aerobic Respiration needs oxygen to release energy from food.

Question 24

Type of respiration

Answer 24

Anaerobic Respiration does not use oxygen to release energy from food.

Question 25

How does oxygen get to our lungs

Answer 25

Oxygen is carried by the haemoglobin in red blood cells to all other cells of the body.

Question 26

Aerobic respiration

Answer 26

Takes place in ALL the living cells in the body as well as in most animal and plant
cells.

Question 27

Anaerobic Respiration

Answer 27

Some living things can get energy from food without using oxygen.

Question 28

Remember

Answer 28

Much less energy is released from food by Anaerobic Respiration than by Aerobic Respiration.

Question 29

Examples of anaerobic respiration

Answer 29

Yeast converts sugars to alcohol in “Fermentation” – this produces alcohol for drinks such as beers and wine!

Question 30

See for yourself

Answer 30

• Have you ever noticed what happens when you breathe on glass??
• Yes as you can see from your experiment water vapour forms on it!
• We can make sure this is water by using cobalt chloride paper

Question 31

Did you know

Answer 31

• When you get a cramp whilst exercising it is caused by the acid that your cells produce when they respire anaerobically (without oxygen).
•
the only reason they do this is because your body needs to produce so much energy while you exercise that not enough oxygen reaches the cells on time.
To try to sort this out you start breathing fast and get out of breath as your lungs are trying to take in as much oxygen as possible!!

Question 32

Breathing

Answer 32

• As you can see from the Equation Oxygen and food are the two important things our cells need to give us energy.
• We’ve learned how the food gets to our cells by digestion.
• The oxygen gets to our cells by breathing!

Question 33

Nose and mouth

Answer 33

• These are the openings the air can enter through!

Question 34

Pharynx

Answer 34

• These are the openings the air can enter through!

Question 35

Trachea

Answer 35

This is the tube that leads into your lungs.
• It is very strong and is kept open by Rings of Cartilage.
• If we didn’t have rings of cartilage what do you think might happen??

Question 36

Bronchus

Answer 36

• As we have two lungs our Trachea divides to branch into each one.

Question 37

Bronchioles

Answer 37

• To spread out through all our lungs the bronchi break up to even smaller little branches called BRONCHIOLES.

Question 38

Alveoli

Answer 38

The final place the air we breathe in goes to in our lung is the ALVEOLI.